Each organelle has cytoplasmFound in plants and animalsProduces hormones and lipids Organelle

A group of a cell can form tissue and systems

The main purpose of a cell is to organize. Cells hold a variety of pieces and each cell has a different set of functions. Some cells move throughout the body, like blood cells. Others are attached to one another like muscle cells, and they stay in one place. Some cells, like skin cells, divide and reproduce quickly. Nerve cells, do not divide or reproduce except under usual circumstances.

The longest cells in the human body are the motor neurons. They can be up to 4.5 feet (1.37 meters) long and run from the lower spinal cord to the big toe.

Cells are specialised to their function. This is known as specialised cells. Each group of specialised cells organises to form what is known as a tissue. For example, the heart muscular cells which organise with each other to form the muscular tissue of the heart wall.